The present invention relates to a device for internal fixation of the bone fragments in a radius fracture.
This device comprises at least one body for abutment against the bone fragments in the radius fracture, and fixing elements which are intended to be locked to the body for fixation of said bone fragments. The body of said device has in a distal end portion at least two predrilled holes for fixing elements, and in a proximal end portion at least two predrilled holes for fixing elements.
Treatment of radius fractures has been a problem both because of the frequency of the injury and because of the difficulty of treating it. The object of the treatment is to restore the congruence and anatomy of the joint, minimise the risk of arthritis and maximise the mobility of the joint.
There are currently a number of possibilities for treating radius fractures.
Closed resetting entails manually resetting or aligning the broken bone and applying a plastercast on the arm. This prevents trauma relating to surgery and is less expensive for the care system. However, it also involves immobility due to the plaster until the bone fragments have healed, which may result in considerable stiffness not confined solely to the wrist and the forearm. The arm being rendered immobile often causes elderly persons considerable stiffness in the fingers, the elbow and the shoulder. The technique is also confined to the simplest and most stable patterns of fracture.
External fixation entails using relatively large-diameter pins introduced into metacarpal bones of the fingers and into the radius above the fracture. The pins are thereafter connected to a rod or frame. Two pins are usually placed in the hand and two in the radius. The frame may also be used for drawing the wrist apart in order to sustain the fracture resetting. External fixation has the disadvantage that the wrist and the hand are kept rigid by the frame, and pins through the skin tend to irritate the tendons and cause cicatrisation. These problems together cause considerable stiffness in both the wrist and the fingers, with loss or impairment of gripping function. Infections may also occur. External fixation does not effect any anatomical resetting of the bone fragments. External fixation is used mainly in severely comminuted fragmented fractures.
Open resetting entails making an incision above the wrist, resetting the bone fragments and using plates, screws or pins as necessary. Open resetting and internal fixation are not commonly used on radius fractures. There is risk of tendon cicatrisation, friction and stiffness. The blood supply to the bone fragments may be disturbed, which may delay or actually prevent their growing together. Drilling holes in, and screwing screws into, small and brittle bone fragments often causes further fragmentation of the latter, thereby further hampering anatomical resetting. Most bone fragments and displacements in ordinary radius fractures are situated on the dorsal side and the irregularity of the radius in this region combines with the many tendons situated close to the bone on this side to make it undesirable to place plates and screws dorsally. As the fractures often comprise a number of small fragments which need resetting, treatment by fixation with plates and screws is difficult.
Percutaneous pinning entails placing small rigid pins through the bone fracture fragments. The pins may be introduced directly through the skin under radiography. Pinning by a percutaneous or limited open technique results in internal fixation of the fracture with a certain further stability internally which is not achieved when the fracture is treated with plastercast only. As the bone fragments are often small and the bone brittle, small-diameter pins are more suitable for the fixation than screws. However, a stable bone adjacent to the bone fragment is required for fastening the pin. If the stable piece of bone is at some distance from, and at an awkward angle to, the bone fragment which is to be pinned, there is great risk that the pin may bend or be displaced. Another problem is that there is often no stable bone element in which to fasten the pin. The use of pins with a tendency to bend or be displaced also means that pinning is rarely done without a plastercast.